Acta Otorrinolaringol Esp. 2010;61(3):184−188 ÓRGANO OFICIAL DE LA SOCIEDAD ESPAÑOLA DE OTORRINOLARINGOLOGÍA Y PATOLOGÍA CÉRVICOFACIAL Y DE LA ACADEMIA IBEROAMERICANA DE OTORRINOLARINGOLOGÍA
Acta Otorrinolaringológica Española
Acta Otorrinolaringológica Española
SEORL PCF
Enero-Febrero 2010. Vol. 61. Núm. 1 Parotidectomías en tumores benignos: clasificación «Sant Pau» de la extensión de la resección Resección de tumor de cuerpo carotideo con LigaSure Laringectomía horizontal supraglótica láser CO : nuestra experiencia en seis años Estudio comparativo mediante tomografía computarizada de la morfología de la sutura timpanoescamosa entre colesteatoma atical y oídos sanos Tensores del velo del paladar y del martillo: vínculos anatómicos, funcionales y sintomáticos Los patrones normal y vestibular en la posturografía dinámica de pacientes con enfermedad de Menière Epidemiología de las epistaxis ingresadas en un hospital de tercer nivel Enero-Febrero 2010. Volumen 61. Número 1. Páginas 1-88
www.elsevier.es/otorrino
Mucormicosis rinoorbitocerebral, un estudio retrospectivo de 7 casos Profilaxis antibiótica en cirugía otorrinolaringológica Recomendaciones de la Comisión para la Detección Precoz de la Hipoacusia (CODEPEH) para 2010 Fallo barorreceptor tras la resección bilateral de paragangliomas carotídeos Miositis fulminante del compartimento muscular cervical posterior. A propósito de un caso Síndrome de sonda nasogástrica: a propósito de un caso Tiroides lingual: un hallazgo casual
Full English text available Incluida en: MEDLINE/Index Medicus EMBASE/Excerpta Medica Concerlit, Aidsline Bibliomed, Biosis, Healfnstar, IBECS
www.elsevier.es/otorrino
ORIGINAL ARTICLE
Cyto-histological correlation in parotid gland tumors Carlos Muñoz Palza,a,* Álvaro Cordero Jiménez,a Rafael Tenor Serrano,a Rafael García Mata,a Purificación Contreras Molina,a and Isabel García Muñozb Servicio de Otorrinolaringología, Hospital Clínico Universitario Virgen de la Victoria, Málaga, Spain Servicio de Anatomía Patológica, Hospital Clínico Universitario Virgen de la Victoria, Málaga, Spain
a
b
Received July 9, 2009; accepted December 3, 2009
KEYWORDS Fine needle aspiration biopsy (FNAB); Parotid gland; Cytohistological correlation
Abstract Objective: To evaluate the usefulness of fine needle aspiration biopsy (FNAB) in the study of parotid gland tumour malignancy in order to plan the most suitable treatment in each case. Material and method: a retrospective study was made of 41 cases, in which we evaluated the correlation between the FNA and the histopathological findings of the surgical piece of parotid gland tumours, from 2004 to 2008, as well as the epidemiological information of these patients. Results: The sensitivity of FNA in the detection of malignancy was 71% and the specificity was of 91%, with a positive predictive value of 62.5% and a negative predictive value of 93.7%. The rate of false negatives was 29% whereas that of false positives was of 9%. Conclusions: The use of the FNA in the study of parotid gland tumours is a useful and simple tool that guides us in the diagnosis and planning of treatment. Nevertheless, it is not exempt from limitations in its diagnostic accuracy. © 2009 Elsevier España, S.L. All rights reserved.
PALABRAS CLAVE Punción aspiración con aguja fina; Glándula parótida; Correlación citohistológica
Correlación citohistológica en tumores de la glándula parótida Resumen Objetivo: Evaluar la eficacia de la citología por punción aspiración con aguja fina (PAAF) en el diagnóstico de malignidad de los tumores de la glándula parótida con el fin de planificar el tratamiento más adecuado para cada caso. Material y método: Se realiza un estudio retrospectivo en una muestra de 41 pacientes, en el que se evalúa la correlación entre la PAAF y los hallazgos histopatológicos de la pieza quirúrgica de los tumores de la glándula parótida, realizado entre los años 2004 y 2008.
*Corresponding author. E-mail address:
[email protected] (C. Muñoz Palza).
0001-6519/$ - see front matter © 2009 Elsevier España, S.L. All rights reserved.
Cyto-histological correlation in parotid gland tumors
185
Resultados: La sensibilidad de la PAAF para detectar malignidad fue de un 71% y la especificidad de un 91%, con un valor predictivo positivo de 62,5% y un valor predictivo negativo de 93,7%. La tasa de falsos negativos fue de 29% mientras que la de falsos positivos de 9%. Conclusiones: La PAAF es un procedimiento diagnóstico de gran utilidad en el diagnóstico de malignidad de tumores de la glándula parótida, que permite establecer el tratamiento más adecuado e individualizado para cada paciente. No obstante, no está exenta de limitaciones en cuanto a su precisión diagnóstica. © 2009 Elsevier España, S.L. Todos los derechos reservados.
Introduction Salivary gland tumours represent 3% of head and neck tumours. They are a heterogeneous group of tumours, due to their great variety and because new histological types are progressively incorporated into their classification. Therefore, carrying out an adequate patient study is vital for reaching an accurate diagnosis and setting the best possible treatment. To do this we use a series of tools such as anamnesis, examination, imaging studies and fine needle aspiration biopsy (FNAB). The definitive diagnosis is provided by the biopsy of the surgical specimen. Fine needle aspiration (FNA) is often used in the study of neoplastic lesions of the parotid gland, although dispute remains with respect to its diagnostic accuracy.1 However, there are clinical situations where it can be a useful tool, for example in the diagnosis of lesions suspected of malignancy, the study of metastatic carcinomas and in lymphomas.2 This technique has been performed for 150 years, but it was not until the decade of the eighties that it began to be used regularly for the study of masses at the level of the salivary glands.3 It is a simple, easily-performed, economical technique, with a low complication rate. It presents disadvantages such as its low sensitivity and negative predictive value (NPV), so FNA has limitations as a screening test. In addition, it maintains reasonable correlation with the final histopathological diagnosis of the surgical specimen.1 The goal of FNA is, above all, to differentiate between benign and malignant lesions. Various studies show that the sensitivity of this technique in the detection of malignancy ranges from 60%-100%, with a specificity of 85%-100%.4,5 Our objective was to evaluate the usefulness of FNA in the study of parotid gland tumours, comparing its results with the final histopathological diagnosis of the surgical specimen.
Material and method A retrospective study was conducted on a sample of 41 patients with different parotid gland tumour pathologies in which we compared the FNAB findings with the histopathological findings of the surgical specimens. The study was conducted between 1st January 2004 and 31st December 2008.
A preoperative FNA and a subsequent partial resection of the gland were performed for all patients during the time period mentioned above. All FNAs were performed at our hospital and reported by a team composed of two pathologists belonging to the Pathological Anatomy Department of the hospital. The surgical resections, all of them partial superficial parotidectomies, were carried out by members of the Otolaryngology Department. The clinical histories were retrospectively reviewed to obtain clinical and pathological data. Demographic (gender, age), clinical, cytological and pathological data were analysed using the statistics program SPSS 11.5. Cytological and histopathological findings were classified as: benign, malignant or no diagnosis. We calculated the sensitivity, specificity, positive predictive value (PPV), NPV and the FNA rate of false positives and negatives, using the histopathological diagnosis of the surgical specimen as standard. Cases with cyto-pathohistological disagreement were reviewed by the same pathologist who reported the FNA, to identify the cause of the error.
Results In the period from 1st January 2004 to 31st December 2008, we carried out 63 surgical procedures on the parotid gland. However, FNA was available prior to surgery for only 41 patients (65%); this group was the basis of our study. With regard to the demographic analysis, 68% (28) of patients were male and 32% (13) were female. The average age was 56 years (range, 16-85 years). Of the 41 FNAs studied, 40 (97.6%) were satisfactory, that is, they enabled a cytological diagnosis to be made; only in 1 case (2.4%) was it unsatisfactory or non-diagnostic, because the sample extracted was acellular, proteinaceous material. Cytology results diagnosed 32 benign lesions and 8 malignant. In the histopathological examination of the surgical specimen, 33 benign and 7 malignant lesions were diagnosed (Tables 1-2). We found 5 true positive cases (malignant cytology and histopathology), 30 true negatives (benign cytology and histopathology), 3 false positives (malignant cytology and benign histopathology) and 2 false negatives (benign cytology and malignant histopathology) (Table 3). With these data we calculated FNA sensitivity for detecting malignancy of 71% and specificity of 91%, PPV of 62.5% and
186
C. Muñoz Palza et al
Table 1 Cytological diagnosis (FNA) in parotid gland tumours Benign Pleomorphic adenoma Warthin’s tumour Monomorphic adenoma Chronic sialadenitis Salivary gland tumour Oncocytic adenoma Normal salivary gland Cyst with acinar arrangement of epithelial cells Simple cyst Granulomatous inflammation Epithelial proliferation Acute inflammatory process Benign cystic lesion Total Malignant Carcinoma Acinar tumour Dyskeratotic squamous cells Squamous cell carcinoma Malignant salivary gland tumour Malignant pleomorphic adenoma Dyskeratotic cells suspicious of malignancy Total Non-diagnostic Proteinaceous material Total
Table 2 Histological diagnosis in parotid gland tumours
No. 9 9 2 2 1 2 1 1 1 1 1 1 1 32
2 1 1 1 1 1 1 8
1 1
NPV of 93.7%. The rate of false negatives was 29%, while the rate of false positives was 9%. The 3 false positive cases corresponded to Warthin’s tumours, which were diagnosed as dyskeratotic cells or squamous cell carcinoma in the FNA (Figure 1). The 2 false negative cases were one muco-epidermoid carcinoma (Figure 2) and one low-grade pleomorphic adenocarcinoma, which were diagnosed in the FNA as adenoma with oncocytic changes and pleomorphic adenoma, respectively (Table 4). The case in which the FNA was not diagnostic because only proteinaceous material was obtained corresponded to a Warthin’s tumour.
Discussion The experience we have gained in the study of parotid gland tumours tells us that FNA is a highly-accurate diagnostic test in differentiating malignant from benign tumours, with a sensitivity and specificity of 71% and 91%, respectively. In our study, PPV was 62.5%, implying that in almost 37.5% of cases, a FNA reported as malignant was a benign lesion. On the other hand, NPV was 93.7%.
No.
Benign Pleomorphic adenoma Warthin’s tumour Monomorphic adenoma Canalicular adenoma Cyst with an epithelial lining Non-specific chronic inflammatory changes Warthin’s tumour with squamous metaplasia foci Benign lymphoepithelial lesion Total
11 17 1 1 1 1 1 1 34
Malignant Acinar cell carcinoma Muco-epidermoid carcinoma Carcinoma Low grade pleomorphic adenocarcinoma Pleomorphic adenoma with a central adenocarcinoma area Muco-epidermoid carcinoma Undifferentiated malignant tumour Total
1 1 1 1 1 1 1 7
Table 3 Cytological and histological diagnoses
Histological diagnosis
Malignant
Benign
Cytological diagnosis (FNA)
Malignant Benign
5 (TP) 2 (FN)
3 (FP) 8 30 (TN) 32
Total
7
33
Total
40
FN indicates false negative; FNA, fine needle aspiration; FP, false positive; TN, true negative; TP, true positive.
Reviewing similar studies published in the medical literature, we found that Cohen2 obtained a PPV of 84% and a NPV of 77%, from a total of 126 parotid lesions. In Spain, Gete4 described a PPV of 86.6% and a NPV of 93.9%. In larger samples, with 382 patients, FNA achieved a sensitivity of 83% and a specificity of 99%, with a PPV of 98% and a NPV of 97%.6 The other studies show specificity between 85%-100% and sensitivity between 54%-98%,5-7 indicating that parotid gland FNA is more accurate for benign tumours than for malignant ones.5 The reason for this ample difference in values is related to technical factors such as insufficient material obtained, puncture site error, performing the technique with the aid of ultrasound and especially to the experience of the pathologist who reported the FNAB. In our case, the pathologist who performed the puncture was not always the same as the one who reported it.
Cyto-histological correlation in parotid gland tumors
Figure 1 A) Fine needle aspiration presenting necrotic base and epithelial cells with dense cytoplasm and polymorphic nuclei (HE 400x). B) Histological section of parotid lesion, showing at high magnification the histology typical of Warthin’s tumour with cystic cavities lined by cuboidal epithelium with oncocytic appearance and lymphoid stroma. The epithelium shows squamous metaplasia and variable cellular atypia (HE 400x).
We observed a total of 29% false negatives. It is common for this error to occur, mostly in malignant mixed tumours and low-grade muco-epidermoid carcinomas due to their heterogeneous cellularity, such as the one observed in our study. This is because muco-epidermoid carcinoma is a malignant neoplasm composed by squamous, mucous and intermediate cells that present varying degrees of cytological atypia. Low-grade lesions with minimal cytological atypia may therefore be confused with benign lesions (Table 4). In our series, the cause of false positives was in all cases due to Warthin’s tumour. This is a benign lesion that usually presents metaplastic changes in the epithelium. This squamous metaplasia, when accompanied by cytological atypia, may lead the pathologist to a false diagnosis of squamous cell carcinoma. It has been reported that acinar cell carcinoma is often erroneously interpreted as a benign lesion in cytology.8 Only
187
Figure 2 A) Fine needle aspiration showing epithelial-like cells, loose and in one-dimensional groups, with very wide cytoplasm and fine chromatin nuclei with evident nucleoli (HE 400x). B) Histological section showing epithelial cell nests with squamous covering, with occasional mucosal cells compatible with a diagnosis of muco-epidermoid carcinoma. Cytological atypia is variable (HE 200x).
52% of malignant lesions were diagnosed by FNAB and among those which were not diagnosed were squamous cell, mucoepidermoid and cystic adenoid carcinomas and lymphomas.9 False negatives are frequently seen in malignant parotid gland tumours, as described in 13%-29% of some series, especially with squamous cell, muco-epidermoid, cystic adenoid and myoepithelial carcinomas and mixed pleomorphic adenocarcinomas.10,11 In our environment, the rate of false negatives is around 19%, identifying similar histopathological strains such as muco-epidermoid, cystic adenoid and acinar cell carcinomas and lymphomas.4
Conclusions A simple, useful tool in the study of parotid gland tumours, FNA can guide us in the diagnosis and individualised planning
188
C. Muñoz Palza et al
Table 4 False positives and negatives in the FNA of salivary glands False positives Cytological diagnosis (FNA) Dyskeratotic squamous cells Squamous cell carcinoma Dyskeratotic cells suspicious of malignancy
Histological diagnosis Warthin’s tumour Warthin’s tumour Warthin’s tumour
False negatives Cytological diagnosis (FNA) Adenoma with oncocytic changes Pleomorphic adenoma
Histological diagnosis Muco-epidermoid carcinoma Low-grade pleomorphic adenocarcinoma
FNA indicates fine needle aspiration.
for each patient. However, it is not without limitations in its diagnostic accuracy, being more accurate for benign tumours than for malignant.
Conflict of interests The authors declare no conflict of interests.
References 1. Herrera Hernández AA, Díaz Pérez JA, García CA. Evaluación de la citología por punción-aspiración con aguja fina en el diagnóstico de cáncer de la glándula parótida. Acta Otorrinolaringol Esp. 2008;59:212-6. 2. Cohen E, Patel S. Fine-Needle Aspiration biopsy of salivary gland lesions in a selected patient population. Arch Otolaryngol Head Neck Surg. 2004;130:773-8. 3. Amedee R, Dhurandhar N. Fine-needle aspiration biopsy. Laryngoscope. 2001;111:1551-7.
4. Gete P, Almodóvar C. Tumores parotídeos: correlación entre la punción aspiración con aguja fina y los hallazgos histopatológicos. Acta Otorrinolaringol Esp. 2006;57:279-82. 5. Contucci AM, Corina L, Sergi B, Fadda G, Paludetti G. Correlation between fine needle aspiration biopsy and histologic findings in parotid masses. Personal experience. Acta Otorhinolaryngol Ital. 2003;23:314-8. 6. Christensen RK, Bjorndal K, Godballe C, Kroydahl A. Value of fine needle aspiration biopsy of salivary gland lesions. Head Neck. 2009 (Epub ahead of print). 7. Bajaj Y, Singh Y, Cozens N, Sharp J. Critical clinical appraisal of the role of ultrasound guided fine needle aspiration cytology in the management of parotid tumours. J Laryngol Otol. 2005;119: 289-92. 8. Alphs HH, Eisele DW, Westra WH. The role of fine needle aspiration in the evolution of parotid masses. Curr Opin Otolaryngol Head Neck Surg. 2006;14:62-6. 9. Atula T, Grenman R, Laippala P, Klemi PJ. Fine-needle aspiration biopsy in the diagnosis of parotid gland lesions: evaluation of 438 biopsies. Diagn Cytopathol. 1996;15:185-90. 10. Zurrida S, Alasio L, Tradati N, Bartoli C, Chiesa F, Pilotti S. Fineneedle aspiration of parotid masses. Cancer. 1993;72:2306-11. 11. Al-Khafaji BM, Nestok BR, Katz RL. Fine-needle aspiration of 154 parotid masses with histologic correlation: ten-year experience at the University of Texas M. D. Anderson Cancer Center. Cancer. 1998;84:153-9.